async-graphql/src/scalars/string.rs

use crate::registry;
use crate::{ContextSelectionSet, GQLOutputValue, GQLType, Result, Scalar, Value};
use std::borrow::Cow;

const STRING_DESC:&'static str = "The `String` scalar type represents textual data, represented as UTF-8 character sequences. The String type is most often used by GraphQL to represent free-form human-readable text.";

impl Scalar for String {
    fn type_name() -> &'static str {
        "String"
    }

    fn description() -> Option<&'static str> {
        Some(STRING_DESC)
    }

    fn parse(value: Value) -> Option<Self> {
        match value {
            Value::String(s) => Some(s),
            _ => None,
        }
    }

    fn parse_from_json(value: serde_json::Value) -> Option<Self> {
        match value {
            serde_json::Value::String(s) => Some(s),
            _ => None,
        }
    }

    fn to_json(&self) -> Result<serde_json::Value> {
        Ok(self.clone().into())
    }
}

impl<'a> GQLType for &'a str {
    fn type_name() -> Cow<'static, str> {
        Cow::Borrowed("String")
    }

    fn create_type_info(registry: &mut registry::Registry) -> String {
        registry.create_type(&Self::type_name(), |_| registry::Type::Scalar {
            name: Self::type_name().to_string(),
            description: Some(STRING_DESC),
        })
    }
}

#[async_trait::async_trait]
impl<'a> GQLOutputValue for &'a str {
    async fn resolve(&self, _: &ContextSelectionSet<'_>) -> Result<serde_json::Value> {
        Ok(self.to_string().into())
    }
}